1. Field of the Invention
This invention relates to electricity meters and more especially but not exclusively it relates to electricity meters for use by domestic consumers.
2. Description of Related Art
A standard electricity credit meter for domestic consumers simply provides a read-out of electricity used. Such meters are read periodically by a meter reader and a bill for the electricity used is sent to the consumer.
Alternatively, a pre-payment meter may be provided for domestic consumers which is arranged to provide a predetermined quantity of electricity to a value corresponding to the value of coins or tokens inserted into the meter.
Further alternatives comprise meters which are arranged to be interrogated remotely via a line link or a radio link for billing purposes and/or meters which can be controlled remotely for effecting tariff changes or for switching the supply on or off in accordance with the time of the day for example.
In these latter cases, a separate dedicated supply may be provided which is controlled remotely or in accordance with signals provided locally by means of a clock.
For the foregoing and other uses, different meters are available, each designed and constructed to suit the particular application in view. It is apparent that in order to provide for possibilities a wide range of different meters are required. With known meters, this requirement has a number of attendant disadvantages, including the high cost of changing from one meter system to another as well as the cost involved in fabricating different meters for different purposes which may each have the same basic functionality.